Special Coverage

Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines

Compensating for Motion Errors in UWB SAR Data

Processing is implemented in two stages by a computationally efficient algorithm.

A method of processing data acquired by ultra-wide-band (UWB) syntheticaperture radar (SAR) provides for suppression of those errors that are caused by the undesired relative motion of the radar platform and the targets. This method involves, among other things, processing of data in the wave-number or frequency domain and the application of motion compensation as a function of the positions of a target relative to the radar platform.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Radar, Radar, Data management

Program for International-Temperature-Scale Calculations

A computer program implements several aspects of the International Temperature Scale of 1990 (ITS90).

Posted in: Briefs, TSP, Software, Measurements, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Thermodynamics, Thermodynamics, Standardization

Updated Global Atmospheric Reference Model Computer Programs

The 1999 version of the NASA/Marshall Space Flight Center Global Reference Atmospheric Model (GRAM-99) and version 3.8 of the Mars Global Reference Atmospheric Model (Mars- GRAM) are the latest in two series of computer programs for calculating selected physical properties of the atmospheres of Earth and Mars, respectively. GRAM-99, like prior versions of GRAM, implements an amalgamation of empirical models that represent geographical, seasonal, and monthly variations of the state of the terrestrial atmosphere (thermodynamic variables and horizontal and vertical wind components) at all altitudes from the ground up to those of spacecraft orbits. Mars-GRAM provides engineering estimates of density, temperature, pressure, and wind components in the Martian atmosphere as functions of latitude, longitude, altitude, and time.

Posted in: Briefs, Software, Mathematical models, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Weather and climate, Thermodynamics, Thermodynamics

Gyroscope Automated Testbed

The Gyroscope Automated Testbed (GAT) is a fully automated inertial device characterization testbed. Rotational response parameterization and shortterm noise stability analysis are the fundamental principles behind the system. Complete response characterization, bias stability, sensitivity, and range are supported along with a drift stability and noise analysis through use of a Green chart and calculation of the power spectral density. GAT is also capable of performing turn-on cycle stability and temperature-dependent testing.

Posted in: Briefs, TSP, Software, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Test equipment and instrumentation

Nanoelectronic Devices With Precise Atomic-Scale Structures

Field-effect transistors with nanometer dimensions are under development.

Since its invention in 1948, the transistor has revolutionized everyday life. The electronics revolution is based on miniaturization of transistors; smaller transistors are faster, and denser circuitry has more functionality. Transistors in the present generation of integrated-circuit chips have sizes of ≈0.18 µm, and the electronics industry has completed development of 0.13-µm transistors, which will enter production within the next few years. Industry researchers are now working to reduce transistor sizes below 0.1 µm — a thousandth of the width of a human hair. However, studies indicate that the miniaturization of silicon transistors will soon reach its limit.

Posted in: Briefs, TSP, Electronics & Computers, Downsizing, Integrated circuits, Transistors, Integrated circuits, Transistors, Nanotechnology

Mounting Flip Chips on Heat-Dissipating, Matched-CTE Boards

Integrated-circuit chips can run cooler, and solder joints are less likely to fail.

“Flip chip on board (FCOB) with high thermal conductivity and tailored coefficient of thermal expansion (CTE)” denotes a developmental concept for relatively inexpensive, lightweight packaging of electronic circuits to accommodate high densities of components and of interconnections. The concept addresses several issues that pertain to flip-chip performance and reliability and to the integration of flip chips with other components: These issues include minimization of undesired mismatches of CTEs between flip chips and printed-wiring boards (PWBs), removal of heat from high-power flip chips, and the need to maximize stiffness while minimizing weight.

Posted in: Briefs, Electronics & Computers, Integrated circuits, Integrated circuits, Conductivity, Thermal testing

Lightweight, Dimensionally Stable Printed-Wiring Boards

In comparison with traditional PWBs, these offer better heat dissipation and CTE matching.

Printed-wiring boards (PWBs) that are especially suitable as substrates for highly reliable, lightweight electronic circuits for aircraft and spacecraft have been developed. Like traditional PWBs, these PWBs are laminated composites that include dielectric inner layers plus copper outer layers that can be etched to form signal and power conductors. Going beyond the designs of traditional PWBs, these PWBs include multiple copper layers separated by dielectric (e.g., polyimide) layers, plus inner cores that contain carbon cloth.

Posted in: Briefs, Electronics & Computers, Integrated circuits, Integrated circuits, Composite materials, Lightweight materials

Protective Solid Electrolyte Films for Thin Li-Ion Cells

These films would simplify fabrication and afford greater flexibility in design.

Thin films of Li2CO3 are under consideration for use as passivating layers between electrodes and solid electrolytes in advanced thin-film lithium-ion electrochemical cells. By suppressing undesired chemical reactions as described below, the Li2CO3 films could help to prolong the shelf lives, increase the specific energies, and simplify the fabrication of the cells. Batteries comprising one or more cells of this type could be used as sources of power in such miniature electronic circuits as those in “smart” cards, implantable electronic medical devices, sensors, portable communication devices, and hand-held computers.

Posted in: Briefs, TSP, Materials, Battery cell chemistry, Integrated circuits, Lithium-ion batteries, Battery cell chemistry, Integrated circuits, Lithium-ion batteries, Electric power, Electrolytes

Study of Turbulent Boundary Layer on the F-15B Airplane

Automated hot-wire anemometry has been demonstrated in flight tests.

NASA’s F-15B #836 is a two-seat version of the F-15, which is a high-performance, supersonic, all-weather fighter airplane. The F-15B is used as a test-bed aircraft for a wide variety of flight experiments. In support of this use, a flight-test fixture (FTF) was developed to provide a space for flight experiments in a region with known aerodynamic conditions. The FTF is a fully instrumented test article mounted on the center line of the bottom of the fuselage of an F-15B airplane. The FTF includes an interchangeable experiment panel and is 107 in. (2.72 m) long, 32 in. (0.81 m) high, and 8 in.(20.3 cm) wide, with a 12-in. (30.5-cm) elliptical nose section. The FTF has been used in many flight experiments during the past several years and can be modified to satisfy a variety of research requirements.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Flight tests, Aerodynamics, Military aircraft

Improved Alignment Mechanism for Robotic Drilling

The improved design prevents jamming of an alignment key in an incorrect position.

An improved alignment mechanism and mating procedure have been devised for a robotic drilling system in which there is a need to assemble drill stem rods for sampling soils and rocks on a distant planet or asteroid. This mechanism is applicable to systems requiring positive axial alignment between segments. Similar mechanisms could be used on Earth, not only for assembling long drills but also for any system where a series of rods must be robotically assembled, such as in truss construction.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Soils, Assembling, Drilling, Robotics

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